The field of electronic data processing has reached a high level of development. Many different kinds of data are processed and exchanged electronically. Data that is exchanged may be required to be protected against an access of unauthorized parties so that the data remain private. Secure computing may include processing and exchanging private data in such a way that privacy of the data is preserved.
Frequently, data that is processed may be represented as strings. The strings may include a sequence of elements, for example characters of the American Standard Code for Information Interchange (ASCII) code or Unicode. The strings may include elements that represent one or more text elements, for example, words or expressions that are meaningful in a language. Strings may be used in different areas for processing and exchanging data.
As an example, an enterprise may have a confidential document such as a purchase order. The enterprise may desire that one or more further entities process the purchase order in such a way that the one or more further entities may not be able to understand the contents of the purchase order. In an example, a data item of the purchase order, for example, a product code may be desired to be identified so that a certain level of privacy is preserved with respect to the purchase order and with respect to the product code. In an example, the purchase order may have a format of a string or may be transformable into the format of a string. The product code may be identifiable in the string representing the purchase order by having a position value at which a substring including the product code starts and having a length value of the substring.